SALT LAKE CITY — Many physicians who see a patient with acute gastroenteritis suggest the patient go home and eat some yogurt, in Dr. Yoram Elitsur's experience. But, most commercial yogurt probably contains too little Lactobacillus species to be of any use, according to his testing of 10 popular brands.
“I am not saying they are cheating us,” Dr. Elitsur, director of pediatric gastroenterology at Marshall University, Huntington, W.Va., said in an interview. “All I am saying is that there is not enough Lactobacillus in there to treat acute gastroenteritis.”
Several studies have suggested that probiotics, such as Lactobacillus and Bifidobacterium species, may be of benefit in treating acute gastroenteritis, reducing the duration of diarrhea. Surprisingly, they may be more effective when the cause of the gastroenteritis is viral, rather than bacterial, Dr. Elitsur said in a poster presentation at the annual meeting of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.
But the concentration of live Lactobacillus species needed to be present is between 109 and 1011 colony-forming units (CFU) per day.
Dr. Elitsur tested 10 brands of yogurt that said on the label that they were live- and active-culture products. He cultured them on Lactobacillus-specific agar plates, and performed polymerase chain reaction (PCR) testing to see if indeed the strains of bacteria in the yogurt were Lactobacillus acidophilus and/or Bifidobacterium bifidum, the probiotics shown most often in other studies to be beneficial in gastroenteritis. He found that only the capsule probiotic (Culturelle) that he tested and used as a control had a concentration of live bacteria in the necessary, recommended amount, and that that product had barely the minimum of 7.7 x 109 CFU. Of the 10 yogurt brands, all but one met the National Yogurt Association's minimum concentration, but none had the concentration necessary to provide a benefit for acute gastroenteritis. The brand that did not meet the National Yogurt Association's minimum concentration of 108 CFU/g was YoBaby (Stonyfield Farm), which had 4.8 x 107 CFU/g.
The other brands tested included Dannon DanActive, Dannon Fruit on the Bottom, Dannon Activia, Yoplait, Breyers Light Probiotic Plus, Breyers Fruit on the Bottom, Kroger Blended, Kroger Fruit on the Bottom, and Great Value.
The PCR testing showed that only three brands had any live Bifidobacterium species.
According to his testing, a child would have to consume about 100 containers of these yogurts in order to get enough probiotic to treat gastroenteritis, Dr. Elitsur said in the interview.
“Anyway you look at it, these companies cannot claim that their yogurt is sufficient to treat gastroenteritis in children,” he said.
But then, none of them do make that specific claim, or they would be subject to drug regulation, he added.
Dr. Elitsur said he had no conflicts of interest with any of the products mentioned.